Common Disease Problems
Botrytis: This fungus causes a grey mold on flowers, leaves, stems and buds. It thrives in cool wet weather conditions. Burpee Recommends: Remove affected plant parts, avoid watering at night and getting water on the plant when watering. Make sure plants have good air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Damping Off: This is one of the most common problems when starting plants from seed. The seedling emerges and appears healthy; then it suddenly wilts and dies for no obvious reason. Damping off is caused by a fungus that is active when there is abundant moisture and soils and air temperatures are above 68 degrees F. Typically, this indicates that the soil is too wet or contains high amounts of nitrogen fertilizer. Burpee Recommends: Keep seedlings moist but do not overwater; avoid over-fertilizing your seedlings; thin out seedlings to avoid overcrowding; make sure the plants are getting good air circulation; if you plant in containers, thoroughly wash them in soapy water and rinse in a ten percent bleach solution after use.
Downy Mildew: This fungus causes whitish grey patches on the undersides and eventually both sides of the leaves. Burpee Recommends: Rotate crops with plants in a different family. Avoid overhead watering. Provide adequate air circulation, do not overcrowd plants. Do not work around plants when they are wet.
Onion White Rot: This soil-borne fungus causes yellowing and wilting of foliage above ground. Below ground, the roots rot and the fungus also infects the bulb. At the base of the bulb, a white fluffy fungus will appear with black fungal bodies. Burpee Recommends: Remove infected bulbs. Practice crop rotation with members of the onion family.
Pink Root Rot: A fungus that attacks onion roots causing them to turn a light pink, then red and eventually purple-brown and causing them to shrivel. Infected plants show signs of nutrient deficiencies and drought because the roots cannot take up water and nutrients. Plants are stunted. The disease lives in the soil for several years and thrives in warm temperatures. Burpee Recommends: Plant as early as possible so the bulk of the plant growth will be in cooler temperatures. Rotate crops and plant resistant varieties.
Rust: A number of fungus diseases that cause rust colored spots on foliage and stalks. Burpee Recommends: Plant early as these diseases tend to be worse later in the season. Plant resistant varieties. Practice crop rotation. Remove infected plants.
Common Pest and Cultural Problems
Leafminers: These insects bore just under the leaf surface causing irregular serpentine lines. The larvae are yellow cylindrical maggots and the adults are small black and yellow flies. They do not usually kill plants, but disfigure the foliage. Burpee Recommends: Remove affected foliage.
Onion Maggot: This insect causes stunted or wilted seedlings and damaged roots and bulbs. The adult is a greyish colored fly which lays its eggs around the base of the plant. The maggots bore into the roots. Burpee Recommends: Remove all bulbs at the end of the season and remove all volunteer wild onion plants. Floating row covers can prevent the females from laying eggs. Check with your Cooperative Extension Service for pest controls.
Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather. Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs to traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
Thrips: Thrips are tiny needle-thin insects that are black or straw colored. They suck the juices of plants and attack flower petals, leaves and stems. The plant will have a stippling, discolored flecking or silvering of the leaf surface. Thrips can spread many diseases from plant to plant. Burpee Recommends: Many thrips may be repelled by sheets of aluminum foil spread between rows of plants. Remove weeds from the bed and remove debris from the bed after frost. Check with your Cooperative Extension Service for pest controls.
Wireworms: These insects live in the soil and kill seedlings by girdling their stems at the soil line, bore into stems, and bulbs. They may be found around the stems in the soil are and ¼ to ¾ inch long, thin, yellow brown worms with a shiny skin. The adults are called click beetles, and are about 1/3 inch long, reddish brown with a hard shell. Burpee Recommends: Rotate crops. Check with your Cooperative Extension Service for pesticide recommendations which must be applied prior to planting.
Will shallots survive snow, ice and cold weather? Yes, and plants should be planted immediately upon receipt. If the ground is frozen, covered in snow, or unworkable hold off on planting until the ground is workable.
If the ground is unworkable, how should I store my shallots? Sets can be stored in a dark, cool, dry place. Plant as soon as possible.
What are the different types of shallots? Grey: elongated, gray-skinned (not sold by Burpee); French: pinkish-brown skin; Dutch: orange-yellow skin; Frog’s Leg: shaped like a frog’s leg (not sold by Burpee).
What parts of the shallot are edible? The clusters of bulbs and leaves.
How can I use shallots as companion plants? Plant shallots with beets, cabbage, carrots, chamomile, mint, sage and thyme. Do NOT plant with beans or peas.